Synopsis

LONG FD_Alloc(
         LONG startfd,
         fd_owner_t owner,
         APTR data,
         LONG * outfd );

Function

Allocate a file descriptor slot for the specified owner.

Inputs

startfd - Starting descriptor number to search from.
owner   - Descriptor owner identifier.
data    - Optional owner data.
outfd   - Pointer that receives the allocated descriptor.

Result

0 on success, or an errno-style error code.

See also

FD_Reserve()

Synopsis

LONG FD_Check(
         LONG fd );

Function

Check whether a descriptor slot is available.

Inputs

fd - Descriptor number to check.

Result

0 if the slot is free, or an errno-style error code.

See also

FD_GetOwner()

Synopsis

LONG FD_Free(
         LONG fd,
         fd_owner_t owner );

Function

Release one reference to a descriptor slot owned by a specific consumer.
The slot becomes available only when its last reference is released.

Inputs

fd     - Descriptor number to release.
owner  - Descriptor owner identifier.

Result

0 on success, or an errno-style error code.

See also

FD_Reserve()

Synopsis

APTR FD_GetData(
         LONG fd );

Function

Query the owner data for a descriptor slot.

Inputs

fd - Descriptor number to query.

Result

Owner data pointer or NULL.

See also

FD_SetData()

Synopsis

fd_owner_t FD_GetOwner(
         LONG fd );

Function

Query the owner of a descriptor slot.

Inputs

fd - Descriptor number to query.

Result

Owner identifier or FD_OWNER_NONE.

See also

FD_Check()

Synopsis

const struct fd_hooks * FD_GetOwnerHooks(
         fd_owner_t owner );

Function

Return the operation hooks registered for an owner.

Inputs

owner - Descriptor owner identifier.

Result

Pointer to the owner's struct fd_hooks, or NULL if none is registered.

See also

FD_SetOwnerHooks() FD_GetOwner()

Synopsis

LONG FD_Reserve(
         LONG fd,
         fd_owner_t owner,
         APTR data );

Function

Reserve a specific file descriptor slot for the specified owner.

Inputs

fd     - Descriptor number to reserve.
owner  - Descriptor owner identifier.
data   - Optional owner data.

Result

0 on success, or an errno-style error code.

See also

FD_Alloc()

Synopsis

LONG FD_Retain(
         LONG fd,
         fd_owner_t owner );

Function

Retain an existing descriptor reservation for an independent table
inheriting the same descriptor number. FD_Free releases one reference;
the number remains reserved until the last reference is released.

The owner data pointer is shared by all references to the reservation;
retaining a number does not retain or copy the object it points to.
The owner must keep that object valid until the final FD_Free(), or
use NULL as the owner data. A non-final FD_Free() leaves the data
pointer unchanged. FD_SetData() replaces it for every reference, not
just the calling table. Owners must synchronize data replacement and
object destruction with their hook users under their own lock.

Inputs

fd - Existing descriptor number.
owner - Expected descriptor owner.

Result

Zero on success, EBADF if the reservation does not match, EINVAL for
FD_OWNER_NONE, or EOVERFLOW if no further reference can be retained.

See also

FD_Reserve() FD_Free()

Synopsis

LONG FD_SetData(
         LONG fd,
         fd_owner_t owner,
         APTR data );

Function

Update the owner data for a descriptor slot.

Inputs

fd    - Descriptor number to update.
owner - Descriptor owner identifier.
data  - Owner data pointer.

Result

0 on success, or an errno-style error code.

See also

FD_GetData()

Synopsis

LONG FD_SetOwnerHooks(
         fd_owner_t owner,
         const struct fd_hooks * hooks );

Function

Register (or clear) the operation hooks for an owner.  The hooks
describe how read()/write()/close()/lseek()/ioctl()/fcntl()/fstat()
act on descriptors created by that owner.

Inputs

owner - Descriptor owner identifier (FD_OWNER_POSIXC, ...).
hooks - Pointer to a persistent struct fd_hooks, or NULL to clear.

Result

0 on success, or an errno-style error code.

Notes

The hooks table must remain valid for as long as descriptors owned by
this owner may be accessed; it is stored by reference, not copied.

See also

FD_GetOwnerHooks()